What is a pixel?
- It is the short form of the picture ( pix ) + element ( el ).
- It is a single point in a graphic image which holds color info. Thousands of pixels arranged in rows and columns appear connected together and make up image.
What is a sub-pixel?
- Each pixel actually composed of three dots a Red, Green, Blue. The three dots must converge at the same point for the image to be sharp, if not the image will be fuzzy.
- Each pixel can have typically three dimensions of variability as Red, Green, Blue. Depending on the intensity of RGB different colors are produced.
How many colors can be produced?
- The number of bits used to represent each pixel determines how many colors can be displayed.
- This is generally called as number of bits per pixel (bpp).
| Bits per pixel | Number of colors |
|---|---|
| 1 bpp | 2 colors |
| 2 bpp | 4 colors |
| 3 bpp | 8 colors |
| 4 bpp | 16 colors |
| 5 bpp | 32 colors |
| 6 bpp | 64 colors |
| 7 bpp | 128 colors |
| 8 bpp | 256 colors |
| 10 bpp | 1024 colors |
| 16 bpp | 65536 colors |
| 24 bpp | 16777216 colors (16.7 million colors) |
| 32 bpp | 4294967296 colors (4294 million colors) |
Pixel density and Screen resolution:
- The quality of image largely depends on pixel density, number of bits used represent each pixel and the resolution of the screen.
- All the above factors can effect the image quality.
What is pixel density?
- It is usually measured in pixels per inch ( ppi ).
- The number of pixels in an inch is known as pixel density.
